The present invention relates to a vehicle with a storage device for electric energy that is rechargeable by way of a charging cable and an external power supply unit.
To externally charge batteries of electrically powered vehicles, the vehicle is usually connected to a stationary power supply device (charging station) by way of a charging cable. A charging socket is needed on the vehicle side to charge plug-in hybrid vehicles (PHEVs) and electric vehicles by way of a cable. This socket is conventionally accessible through a charging flap provided in the car body, analogously to a fuel tank filler neck hidden behind a fuel door. This charging socket forms an electrical connecting element located behind the charging flap.
With respect to the charging infrastructure, what are known as Mode 2 and Mode 3 charging have become established. In the case of Mode 2 charging using a household socket outlet, an in-cable box including a protective device (residual-current circuit interrupter) is provided in the cable, and in the case of Mode 3 charging, this protective device is present in the charging station. In some instances, the charging cable is fixedly attached to the charging station.
Thus, plug-in hybrid vehicles so far have needed an additional charging flap for the charging connector, in addition to the fuel door. Since hybrid vehicles, and also all-electric vehicles, are generally derived from conventional vehicles, this means that additional variants of the car body have to be provided. In cases in which dedicated body variants have to be generated, the costs in the individual case are extremely high since a specific body variant has to be created for each base body (right-hand/left-hand drive car, convertible, station wagon, and the like). Providing such a charging flap in the body, possibly in addition to a fuel door, is therefore not only complex since more than one specific body variant must be provided for electric vehicles in one vehicle family, but additionally a flap mechanism has to be developed, manufactured and installed, thereby increasing the costs for an electric vehicle. At times, the installation space for a charging flap along with a charging socket is also not available. In particular, when the charging cable is fixedly installed in the vehicle and is to be extendible through an opening behind a charging flap, it is difficult to find an installation location for a charging flap behind which sufficient space is available for the charging cable and a roll-up mechanism. In any case, the present position of a charging flap on the vehicle side wall is out of the question.
Moreover, it is frequently also undesirable for design reasons to provide such added flaps in the body. It would thus be advantageous if existing body openings could be utilized to feed through a charging cable.
WO 2012/172626 shows and describes a ribbon cable-type charging cable for an electric vehicle, which can be wound onto a safekeeping device in the vehicle interior and guided out through an opening that is provided in the rear bumper and separate from the luggage compartment opening. This separate opening can be closed by way of a flap, but only if the cable is not fed through the opening.
DE 10 2009 016 895 A1 shows and describes a charging connector device for an electrically powered vehicle. A round cable that can be wound onto a cable reel is guided out of the vehicle interior through a body opening that is separate from the luggage compartment opening. This separate body opening can be closed by way of a flap. At the lower edge, the flap has an outwardly curved projection, which creates a groove forming a passage for the round cable. In this way, this body flap can be moved into the closed position thereof even when the round cable is guided out. A seal is provided between the body and the flap; a sealing lip is also provided in the groove. A guide element for the cable is provided on the body side in the region of the groove.
FR 2 959 462 A1 describes and shows a cable feedthrough for a charging cable of an electrically powered vehicle, in which the charging cable having a round cross-section is accommodated in a tailgate of the vehicle and can be pulled out of the same to the outside. The charging cable exiting the tailgate is located outside the tailgate seal, whereby it is not guided out of the body between the tailgate and the body seal thereof.
A charging station for electric vehicles including a cable roll-up system is known from DE 10 2011 051 052 A1, in which the conventional charging cable is wound onto a winding reel. This winding reel can be driven by way of a motor.
WO 2009/091745 A2 also shows a charging station having a charging cable that can be wound onto a winding reel, wherein the charging cable is composed of two round wires that are joined to and disposed next to one another. Guiding elements upstream of the winding reel ensure that the cable does not twist as it is wound up.
From DE 10 2009 046 327 A1, an electric vehicle having an installed conventional charging cable that is wound onto a winding reel and can be unwound therefrom is known, for which purpose the cable can be pulled out of an opening provided on the side of the vehicle.
A roll-up or winding mechanism provided in the vehicle for the charging cable is prone to malfunctions because existing concepts make it necessary to provide sliding contacts for winding up the cable. Such sliding contact connections are expensive and prone to faults. In particular, it must be ensured that the protective ground conductor is always connected. Furthermore, roll-up mechanisms are always problematic because they become hot due to ohmic losses in the cable when the cable is not completely unwound and due to poor heat dissipation.
DE 10 2011 121 303 A1 shows a vehicle having a charging cable that can be pulled out of a lateral opening, wherein the charging cable is accommodated in a cable safekeeping device in the vehicle located behind a separate body flap. The cable safekeeping device is provided with a deflection roller upon which a spring acts and over which the cable is guided, and which is displaced in a translational manner against the force of the spring in the cable safekeeping device when the charging cable is being pulled out of the cable safekeeping device.
A similar cable safekeeping device which is provided in a motor vehicle, but equipped with a plurality of individual deflection rollers, which are each acted upon by a spring and displaceable against the spring force, is known from DE 10 2009 057 659 A1.
These known cable safekeeping devices including deflection rollers for the cable, however, take up a large installation space in the vehicle, which generally is not available for these purposes. Moreover, there is a risk that the cable twists about the longitudinal axis thereof over the course of the useful life and slides out of the deflection rollers or blocks them.
It is the object of the present invention to provide a vehicle with a storage device for electric energy that is rechargeable by way of an external power supply unit, in which separate body flaps for connecting the charging cable can be dispensed with.
This and other objects are achieved by a vehicle according to the invention comprising a storage device for electric energy that is rechargeable by way of an external power supply unit and a body that comprises at least one body opening closable by way of a body flap. A charging cable is provided, which is electrically conductively connected or connectable to the storage device and runs at least in regions in the interior of the body. The body opening is a luggage compartment opening or a door opening, and the body flap is a trunk lid or a door of the vehicle. The charging cable is designed as a flexible ribbon cable or comprises at least one flexible ribbon cable section. The flexible ribbon cable, or the at least one flat ribbon cable section, can be fed through a body gap present between an edge of the body opening and the body flap, and the ribbon cable, or the at least one flexible ribbon cable section, comprises current-carrying conductors, which are disposed next to one another and designed as flat, ribbon-shaped conductors and surrounded by a shared, electrically insulating sheath.
This embodiment of the vehicle makes it possible to utilize existing body openings, such as a luggage compartment opening or a vehicle door opening, to feed the charging cable through, so that no additional body flap has to be provided for connecting the electrical storage device of the vehicle to an external power supply device. Equipping the vehicle with the special charging cable allows the body opening to be closed by way of the associated body flap (trunk lid or vehicle door) while the charging cable is fed through, wherein the charging cable implemented as a flexible ribbon cable is fed through the body gap present between the edge of the body opening and the edge of the body flap in the closed state. Thus, no special provision for the cable feedthrough is necessary, neither on the body flap, nor on the edge of the body opening.
The charging cable, which according to the invention is designed as a very flat, flexible ribbon cable or is provided with at least one very flat, flexible ribbon cable section, can be easily and safely fed with the ribbon cable section between the edge of the existing body opening and the body flap closing the opening. Due to the high flexural elasticity inherent in the design, the ribbon cable section is suitable for conforming to the contours of the body and the body flap, so that the ribbon cable section can be clamped between the edge of the body opening and the closed body flap without the risk of damage in the region of the seal of the body opening, and is not crushed. Due to the particularly flat and highly flexurally elastic configuration of the ribbon cable, or of the ribbon cable section, it is not necessary to provide a large gap dimension between the closed body flap and the body in the region of the cable feedthrough. The low thickness of such a ribbon cable or ribbon cable section, and the high flexural elasticity thereof, which allows very tight bending radii about an axis extending parallel to the longer transverse extension of the ribbon cable or of the ribbon cable section, are made possible by designing the electrical conductors as flat conductors in the ribbon cable or in the ribbon cable section.
In one variant of the invention, it may be provided that the charging cable includes a vehicle-side charging cable portion that is electrically conductively connected to the storage device and an external charging cable portion that is connected to the vehicle-side charging cable portion, or can be connected by way of an electrical connecting device, wherein a vehicle-side connecting element of the connecting device is electrically connected to the vehicle-side charging cable portion, and wherein an external connecting element of the connecting device is electrically connected to the external charging cable portion.
One embodiment should be particularly emphasized, in which the charging cable designed as a ribbon cable, when idle, is accommodated on a cable receiving device provided in the interior of the body, and for use can be pulled out of the body opening. Using a ribbon cable, which is to say a cable having a flat cross-section, as the charging cable has the advantage that the cable can be easily supported in the cable receiving device, so that cable torsion can be effectively prevented, whereby the reliability of the cable roll-up mechanism is increased. Moreover, as was already described, the ribbon cable can take on a very small bending radius in the direction of the small cross-section and conform closely to the contour in the region of the body opening. The elasticity of the seal present in the region of the body opening is usually such that it allows the small cable cross-section.
The cable receiving device can include a winding mechanism, onto which the ribbon cable can be wound. In this case, it is advantageous if a temperature sensor is provided in the region of a winding reel winding up the ribbon cable. The temperature sensor causes the charging process to be shut down or the output to be reduced so as to prevent impermissible heating of the charging cable.
Particularly preferred is one embodiment in which the cable receiving device has a tackle-like retraction mechanism, in which the ribbon cable is guided over at least one deflection roller acted upon by a tensile force from an elastic element.
One advantageous refinement of such a retraction mechanism is for the deflection roller acted upon by a tensile force from an elastic element to be part of a movable deflection roller system composed of a plurality of deflection rollers collectively acted upon by the tensile force from the elastic element, wherein the ribbon cable is guided over each of the deflection rollers of the movable deflection roller system, and the ribbon cable is also guided over at least one fixed deflection roller, in addition to the deflection roller acted upon by the tensile force from the elastic element.
It is particularly advantageous if the fixed deflection roller is part of a stationary deflection roller system composed of a plurality of fixed deflection rollers, wherein the ribbon cable is guided over each of the fixed deflection rollers of the stationary deflection roller system.
This retraction mechanism follows the principle of a tackle. Due to the small bending radius of the ribbon cable, said “tackle” can be implemented in a very flat manner using small rollers. Since the individual cable sections accommodated in this retraction mechanism do not bear on one another, but define spaces between each other, heat dissipation, such as by air convection, is possible. As a result, the maximum current flow is possible, regardless of the degree to which the cable is extended.
The deflection rollers enable a clear guidance of the ribbon cable from the point at which the cable is guided to the outside through the gap between the body opening and the body flap, up to the retraction mechanism.
The retraction mechanism may be disposed in a suitable location in the luggage compartment, for example. The defined cable guidance also allows the cable to be housed in a cable duct to protect the charging cable. For this purpose, the vehicle can advantageously be provided with a cable guiding device in the region of the inner edge of the body opening, by way of which the ribbon cable can be guided from the cable receiving device to the edge of the body opening.
The ribbon cable is preferably fed through a cable cleaning device upstream of the cable receiving device. The self-cleaning of the charging cable thus made possible during retraction into the cable receiving device ensures that the portion of the charging cable located in the vehicle remains clean. It is likewise advantageous that the charging cable must only be extended to such a length as is actually required in each case. Thus, only a small portion, or no portion, of the charging cable will ever be located outside the vehicle on the ground. Since the cleaning mechanism can also wipe off water, freezing of the charging cable accommodated in the cable receiving device is prevented.
The solution according to the invention makes it possible to very conveniently carry out the connection and disconnection process of the charging cable, while storing the charging cable in a protected manner in the luggage compartment. It is not necessary to first roll up the cable manually and store it in the vehicle in a location that is separate from the charging flap.
The invention also includes a charging cable, in particular a charging cable for use in a vehicle according to the invention. In the charging cable according to the invention, in particular for use with a vehicle having a storage device for electric energy rechargeable by way of an external power supply unit, which is designed as a ribbon cable or comprises at least one ribbon cable section, the flexible ribbon cable, or the at least one flexible ribbon cable section, has flat, ribbon-shaped current-carrying conductors that are disposed next to one another and surrounded by a shared, electrically insulated sheath. As seen looking at the cross-section, the flexible ribbon cable, or the at least one flexible ribbon cable section, includes an upper and a lower flat protective ground conductor above and/or beneath the flat, ribbon-shaped current-carrying conductors, the protective ground conductor being likewise surrounded by a shared, electrically insulating sheath (insulation).
The ribbon cable, or the at least one ribbon cable section, preferably additionally includes a signal conductor, which is likewise surrounded by the shared, electrically insulating sheath. This signal conductor is preferably likewise flat and designed in the same manner as the current-carrying conductors.
In one advantageous embodiment of the charging cable, the flat, ribbon-shaped electrical conductors are each formed by wire mesh. Alternatively, the flat, ribbon-shaped electrical conductors can each be composed of a plurality of electrically conducting layers located on top of one another. The flat, ribbon-shaped current-carrying conductors and also the protective ground conductors can thus be formed, for example, by a thin metal strip, multiple metal strips that are located on top of and are movable relative to one another and that form thin electrically conducting layers, or a ribbon-like mesh of thin electrically conducting wires. This composition and the provision of only a single shared electrically insulating sheath ensures high flexural elasticity of the flat charging cable and enables very small bending radii, so that the flat charging cable can easily conform to the body shape in the region of the opening edge and to the shape of the edge of the body flap.
The ribbon cable or the at least one ribbon cable section preferably has a flat upper face and a flat lower face. It is also advantageous if the ribbon cable or the at least one ribbon cable section is provided with a soft, elastic surface at least in regions.
In one advantageous refinement of the charging cable according to the invention, the at least one ribbon cable section is electrically connected to a first cable section of the charging cable by way of a first contacting device and to a second cable section by way of a second contacting device. At least one of the two contacting devices is provided with a soft, elastic surface.
The composition according to the invention of the charging cable comprising the at least one flat protective ground conductor, which is in particular suitable for use in the vehicle according to the invention, has the advantage that, in the case of damage to the ribbon cable section, for example due to improper handling, the protective ground conductor is always disposed between the current-carrying conductors and the body or the body flap, so that the likelihood that a current-carrying conductor makes contact with ground when a ribbon cable section is damaged is significantly reduced.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.